Library Open Repository

Zn-Pb-Cu volcanic-hosted massive sulphide deposits: criteria for distinguishing brine pool-type from black smoker-type sulphide deposition

Downloads

Downloads per month over past year

Solomon, M and Tornos, F and Large, RR and Badham, JNP and Both, RA and Zaw, K (2004) Zn-Pb-Cu volcanic-hosted massive sulphide deposits: criteria for distinguishing brine pool-type from black smoker-type sulphide deposition. Ore Geology Reviews, 25. pp. 259-283. ISSN 0169-1368

[img] PDF
criteria_paper.pdf | Request a copy
Full text restricted
Available under University of Tasmania Standard License.

Abstract

Eight Zn-Cu massive sulphide deposits that appear to have formed on the sea floor (seven in Spain, one in Tasmania) are believed to have been precipitated in brine pools, based on the salinities and temperatures of fluid inclusions in underlying stockworks. Comparing the geological features of these deposits with those of the Zn-Cu massive sulphide ores of the Hokuroku Basin, Japan, which have formed as mounds from buoyant fluids of low salinity, shows that brine pool deposits have: (1) potentially very large size and tonnage, and high aspect ratio, (2) higher Zn/Cu and Fe/Cu values, (3) no evidence of chimneys, (4) relatively abundant framboidal pyrite and primary mineral banding, (5) reduced mineral assemblages (pyritearsenopyrite/ pyrrhotite), and minor or rare barite in the massive sulphide, (6) associated stratiform and/or vein carbonates, (7) relatively unimportant zone refining, (8) lack of vertical variation in sphalerite and sulphur isotopic compositions, and (9) evidence of local bacterial sulphate reduction. Application of these criteria to the Rosebery deposit in Tasmania, for which there are no fluid inclusion data, leads to the conclusion that the southern section was deposited as separate lenses in a brine-filled basin or basins. Other potential candidates include Brunswick no. 12 and Heath Steele (Canada), Woodlawn and Captains Flat (New South Wales), Hercules and Que River (Tasmania), and Tharsis and the orebodies at Aljustrel (Spain and Portugal). Recently published fluid inclusion data for Gacun (China) and Mount Chalmers (Queensland) suggest that not all ores deposited from highly saline fluids have reduced mineral assemblages.

Item Type: Article
Keywords: Massive sulphides; Criteria; Brine pools, VHMS, VMS, ore genisis, mounds
Journal or Publication Title: Ore Geology Reviews
Page Range: pp. 259-283
ISSN: 0169-1368
Identification Number - DOI: 10.1016/j.oregeorev.2004.01.003
Date Deposited: 16 Feb 2007
Last Modified: 18 Nov 2014 03:13
URI: http://eprints.utas.edu.au/id/eprint/759
Item Statistics: View statistics for this item

Repository Staff Only (login required)

Item Control Page Item Control Page